Old MacBook keeps showing iCloud message after migration

Hello:

I am going to do my best to describe this problem accurately.

I have a 2019 MacBook Pro. I also have a 2023 Mac Studio that I used Migration Assistant to successfully transfer everything off of the MacBook and on to the Mac Studio. This is the problem:

I still use the MacBook. But every time I sign in or try to use the MacBook I get a message about not being able to connect to iCloud. (It is the correct iCloud address that I now use on the Mac Studio.)

I get one of two options: 1. Apple ID Settings 2. Later

When I go into Apple ID Settings and use the password for either the Mac Studio or the MacBook it tells me it is an invalid password.

When I hit "Later" the message just comes back again, sometimes multiple times. Sometimes it even pops up randomly while using the laptop. Which is a problem because I still use it for other things and it looks pretty bad, not to mention extremely annoying when it randomly pops up in the middle of a project.

How do I get this to stop? Anyone have any ideas or had this problem themselves? I've tried just about everything I know at this point. Thank you!!